This invention relates to an automatic gain control circuit suitable for use in a radio receiver.
Generally, an automatic gain control circuit is coupled to an amplifier to automatically control the gain of the amplifier. It is preferred to manufacture such an automatic gain control circuit as a semiconductor integrated circuit. The automatic gain control circuit should have little temperature dependency. As will later be described with reference to one of a few figures of the accompanying drawing, a conventional automatic gain control circuit is not suitable for semiconductor integration because a capacitor is indispensible to couple the circuit to the amplifier. In addition, temperature dependency is serious. Moreover, a stabilized circuit should be coupled to the circuit and the amplifier to supply them with a stabilized voltage in case that an electric source voltage is liable to vary.